1. A man-child applies an effort force of 30 N to a log on a boulder that has a resistance of 30 N. What is the mechanical advantage of the log?
2. A worker uses an iron bar to raise a trailer. The effort arm is 8 m long. The resistance arm is 2 m long. What is the mechanical advantage of the bar?
3. Jake drives a tractor that has a wheel radius of 270 cm. Its axle has a radius of 30 cm. What is the
mechanical advantage Jake’s tractor?
4. What is the mechanical advantage for a ramp that is 2000 cm long, and 40 cm high?
5. What is the efficiency of the machine if 240 joules are put into the egg beater and 180 joules are applied to the cookie dough?
6. What is the power needed to raise a 300 Kg object on Earth 400 m in 2 seconds?
7. What is the power needed to raise an object 60 m in 200 seconds with 1 N?
ANSWERS
1. A man-child applies an effort force of 30 N to a log on a boulder that has a resistance of 30 N. What is the mechanical advantage of the log?
MA= Fr / Fe
Fr = resistance force
Fe = effort force
30 N / 30 N = 1 T.M.E. (No mechanical advantage)
2. A worker uses an iron bar to raise a trailer. The effort arm is 8 m long. The resistance arm is 2 m long. What is the mechanical advantage of the bar?
MA = Le / Lr
Le = length of effort arm
Lr = length of resistance arm
MA = 8 m / 2 m
MA = 4 T.M.E.
3. Jake drives a tractor that has a wheel radius of 270 cm. Its axle has a radius of 30 cm. What is the mechanical advantage Jake’s tractor?
MA = rw/ ra
rw = radius of wheel
ra = radius of axle
MA = 270 cm/ 30 cm = 9 T.M.E.
4. What is the mechanical advantage for a ramp that is 2000 cm long, and 40 cm high?
MA = length/ height
MA = 2000 cm / 40 cm = 50 T.M.E.
5. What is the efficiency of the machine if 240 joules are put into the egg beater and 180 joules are applied to the cookie dough?
Efficiency =Work out=180 j= 75 %
Work in 240 j
6. What is the power needed to raise a 300 Kg object on Earth 400 m in 2 seconds?
Power=F * d F=ma
t
F=300 Kg(9.8 m/s) = 2940 N
P= 2940 N(400 m)=588,000 W
2 sec.
7. What is the power needed to raise an object 60 m in 200 seconds with 1 N?
P= F*d
t
P= 1N(60 m)=0.3 W
200 sec.
1. A worker applies an effort force of 15 N to pry open a window that has a resistance of 320 N. What is the mechanical advantage of the crowbar?
2. A worker uses an iron bar to raise a manhole cover. The effort arm is 60 cm long. The resistance arm is 12 cm long. What is the mechanical advantage of the bar?
3. What is the mechanical advantage of a machine with a wheel radius of 55 cm, and an axle radius of 5 cm?
4. What is the mechanical advantage for a ramp that is 15 feet long, and 2.5 feet high?
5. How much force would be needed to move an object 5 m from the fulcrum, if you supply 40 N of force on the end of a lever that is 15 m long?
6. What is the power needed to raise a 25 Kg object on Earth 5 m in 5 seconds?
7. What is the power needed to raise an object 10m in 5 seconds with 30 N?
1.A worker applies an effort force of 15 N to pry open a window that has a resistance of 320 N. What is the mechanical advantage of the crowbar?
MA= Fr / Fe
Fr = resistance force
Fe = effort force
320 N / 15 N = 21.33 T.M.E.
2.A worker uses an iron bar to raise a manhole cover. The effort arm is 60 cm long. The resistance arm is 12 cm long. What is the mechanical advantage of the bar?
MA = Le / Lr
Le = length of effort arm
Lr = length of resistance arm
MA = 60 cm / 12 cm
MA = 5 T.M.E.
3.What is the mechanical advantage of a machine with a wheel radius of 55 cm, and an axle radius of 5 cm?
MA = rw/ ra
rw = radius of wheel
ra = radius of axle
MA = 55 cm/ 5 cm = 11 T.M.E.
4.What is the mechanical advantage for a ramp that is 15 feet long, and 2.5 feet high?
MA = length/ height
MA = 15 ft. / 2.5 ft. = 6 T.M.E.
5.How much force would be needed to move an object 5 m from the fulcrum, if you supply 40 N of force on the end of a lever that is 15 m long?
LEVER
** Work in = Work out
Force X distance(effort) = Force X distance(resistance)
(40 N )(15 m) =(X N)(5 m) X= 120 N
6.What is the power needed to raise a 25 Kg object on Earth 5 m in 5 seconds?
Power=F * d F=ma
t
F=25 Kg(9.8 m/s2) = 245 N
P= 245 N(5 m)=245 W
5 sec.
7.What is the power needed to raise an object 10m in 5 seconds with 30 N?
P= F*d
t
P= 30 N(10 m)=60 W
5 sec.
1.How much force would be needed to move an object 10 m from the fulcrum, if you supply 30 N of force on the end of a lever that is 20 m long?
2. A worker uses an iron bar to raise a manhole cover. The effort arm is 20 cm long. The resistance arm is 5 cm long. What is the mechanical advantage of the bar?
3. A wheel has a radius of 75 cm. Its axle has a radius of 15 cm. What is the mechanical advantage of the wheel?
4. What is the mechanical advantage for a ramp that is 12 m long and 3 m high?
5. What is the efficiency of the machine if 4500 joules are put into the unicycle and 150 joules are applied to the ground by the unicycle?
6.What is the power needed to raise a 10,000 g object on Earth 20 m in 40 seconds?
7. What is the power needed to raise an object 80 m in 2 minutes with 5000 N?
ANSWERS BELOW
1. How much force would be needed to move an object 10 m from the fulcrum, if you supply 30 N of force on the end of a lever that is 20 m long?
** Work in = Work out
Force X distance(effort) = Force X distance(resistance)
(30 N )(20 m) =(X N)(10 m) X= 60 N
2. A worker uses an iron bar to raise a manhole cover. The effort arm is 20 cm long. The resistance arm is 5 cm long. What is the mechanical advantage of the bar?
MA = Le / Lr
Le = length of effort arm
Lr = length of resistance arm
MA = 20 cm / 5 cm
MA = 4 T.M.E
3. A wheel has a radius of 75 cm. Its axle has a radius of 15 cm. What is the mechanical advantage of the wheel?
MA = rw/ ra
rw = radius of wheel
ra = radius of axle
MA = 75 cm/ 15 cm = 5 T.M.E
4. What is the mechanical advantage for a ramp that is 12 m long and 3 m high?
MA = length/ height
MA = 12 m / 3 m= 4 T.M.E
5.What is the efficiency of the machine if 4500 joules are put into the unicycle and 150 joules are applied to the ground by the unicycle?
Efficiency =Work out=150 j(100%)= 3.3 %
Work in 4500 j
6.What is the power needed to raise a 10,000 g object on Earth 20 m in 40 seconds?
Power=F * d F=ma
t
F=10 Kg(9.8 m/s) = 98N
P= 98 N(20 m)=49 W
40 sec.
7. What is the power needed to raise an object 80 m in 2 minutes with 5000 N?
P= F*d
t
2 minutes(60 sec/min)=120 sec
P= 5000(80)/)= 3,333.3 W
120 sec.
1. A worker applies an effort force of 20 N to pry open a window that has a resistance of 40 N. What is the mechanical advantage of the crowbar?
2. A worker uses an iron bar to raise a manhole cover. The effort arm is 500 cm long. The resistance arm is 50 cm long. What is the mechanical advantage of the bar?
3. A motorcycle has a wheel radius of 60cm. Its axle has a radius of 2 cm. What is the mechanical advantage of the motorcycle?
4. What is the mechanical advantage for a ramp that is 10 meters long, and 2 meters high?
5. What is the efficiency of the machine if 40 Kj are put into the car and 10 Kj are applied to the ground by the car?
6. What is the power needed to raise a 50,000 g object on Earth 20 m in 100 seconds?
7. What is the power needed to raise an object 6 m in 20 seconds with 30 N?
ANSWERS
1. A worker applies an effort force of 20 N to pry open a window that has a resistance of 40 N. What is the mechanical advantage of the crowbar?
MA= Fr / Fe
Fr = resistance force
Fe = effort force
40 N / 20 N = 2 T.M.E.
2. A worker uses an iron bar to raise a manhole cover. The effort arm is 500 cm long. The resistance arm is 50 cm long. What is the mechanical advantage of the bar?
MA = Le / Lr
Le = length of effort arm
Lr = length of resistance arm
MA = 500 cm / 50 cm
MA = 10 T.M.E.
3. A motorcycle has a wheel radius of 60 cm. Its axle has a radius of 2 cm. What is the mechanical advantage of the motorcycle?
MA = rw/ ra
rw = radius of wheel
ra = radius of axle
MA = 60 cm/ 2 cm = 30 T.M.E
4. What is the mechanical advantage for a ramp that is 10 meters long, and 2 meters high?
MA = length/ height
MA = 10 m / 2 m = 5 T.M.E.
5. What is the efficiency of the machine if 40 Kj are put into the car and 10 Kj are applied to the ground by the car?
Efficiency =Work out=10 Kj= 25 %
Work in 40 Kj
6. What is the power needed to raise a 50,000 g object on Earth 20 m in 100 seconds?
Power=F * d F=ma
t
50,000 g =50Kg
F=50 Kg(9.8 m/s2) = 490 N
P= 490 N(20 m)=98 W
100 sec.
7. What is the power needed to raise an object 6 m in 20 seconds with 30 N?
Power=F * d W=Fd
t
P= 30 N(6 m)=9 W
20 sec.
1. A worker applies an effort force of 6 N to pry out a nail that has a resistance of 30 N. What is the mechanical advantage of the Hammer?
2. A worker uses a branch to raise a tree off a friend. The effort arm is 10 m long. The resistance arm is 2 m long. What is the mechanical advantage of the branch?
3. How far would the object be from the fulcrum if 60 N of force balanced the 30 N of force on the end of a lever that is 20 m long?
4. What is the mechanical advantage for a ramp that is 60 m long, and 12 m high?
5. What is the efficiency of the bull dozer if 15,000 joules are put into the dozer and 750 joules are applied to the ground by the dozer?
6. What is the power needed to raise a 25 Kg object on Earth 10 m in 500 seconds?
7. What is the power needed to raise an object 10 m in 1 minute with 60 N?
1. A worker applies an effort force of 6 N to pry out a nail that has a resistance of 30 N. What is the mechanical advantage of the Hammer?
MA= Fr / Fe
Fr = resistance force
Fe = effort force
30 N / 6 N = 5 T.M.E.
2. A worker uses a branch to raise a tree off a friend. The effort arm is 10 m long. The resistance arm is 2 m long. What is the mechanical advantage of the branch?
MA = Le / Lr
Le = length of effort arm
Lr = length of resistance arm
MA = 10 cm / 2 cm
MA = 5 T.M.E.
3. How far would the object be from the fulcrum if 60 N of force balanced the 30 N of force on the end of a lever that is 20 m long?
** Work in = Work out
Force X distance(effort) = Force X distance(resistance)
(60 N )(X m) =(30 N)(20 m) X= 10 m
4. What is the mechanical advantage for a ramp that is 60 m long, and 12 m high?
MA = length/ height
MA = 60 m / 12 m = 5 T.M.E.
5. What is the efficiency of the bull dozer if 15,000 joules are put into the dozer and 750 joules are applied to the ground by the dozer?
Eff. =Work out =750 j(100)= 5 %
Work in 15,000 j
6. What is the power needed to raise a 25 Kg object on Earth 10 m in 500 seconds?
Power=F * d F=ma
t
F=25 Kg(9.8 m/s2) = 245 N
P= 245 N(10 m)= 4.9 W
500 sec.
7.What is the power needed to raise an object 10 m in 1 minute with 60 N?
P= F*d
t
1 minute = 60 seconds
P= 60 N(10 m)= 10 W
60 sec.