PHY 111 FINAL EXAM PRACTICE EVALUATION
2026 QUESTION BANK FULL SOLUTION SET
◉ A car is traveling at 10 m/s. Report answer (a) in m/s.
a. How fast would the car have to go to double its kinetic energy?
b. By what factor does the car's kinetic energy increase if its speed is
doubled to 20 m/s?
Answer: a.
KE = 1/2 * M * V^2
KE at 10m/s is 1/2 * M * 100 = 50 * M
Energy twice that is 100*M
100 * M = 1/2 * M * V^2
200 = V^2
V = sqrt(200)
V=14.14 m/s to double KE
,b.
KE = 1/2 * M * V^2
KE is proportional to square of velocity so doubled=2 times so
2^2=4
Example: if M=5 and V=10:
KE=1/2*5*10^2
KE=250
doubled-
KE=1/2*5*20^2
KE=1000
1000/250=4
◉ a. A 100 g ball is thrown straight up in the air from a height of 1.5
m above the floor. The ball just reaches the ceiling 10 m above the
floor. What was the initial speed of the ball?
, b. What speed will the ball have the instant before it hits the floor?
Answer: a.
Vf^2=Vo^2-2as
2(9.8) (10-1.5)=Vo^2
Vo=12.9m/s
b.
PE=mgh
KE=1/2mv^2
mgh=1/2mv^2
2gh=v^2
v=sqrt(2(9.8)10)
v=14 m/s
◉ a. Calculate the power required for a 1,400 kg car to climb a 10
degree hill at a steady 80 km/hr.
b. Calculate the power required of a 1,400-kg car to pass another car
on a level road accelerating from 90 to 110 km/hr in 6 seconds.
Assume the retarding force on the car is 700 N throughout.
Answer: a.
2026 QUESTION BANK FULL SOLUTION SET
◉ A car is traveling at 10 m/s. Report answer (a) in m/s.
a. How fast would the car have to go to double its kinetic energy?
b. By what factor does the car's kinetic energy increase if its speed is
doubled to 20 m/s?
Answer: a.
KE = 1/2 * M * V^2
KE at 10m/s is 1/2 * M * 100 = 50 * M
Energy twice that is 100*M
100 * M = 1/2 * M * V^2
200 = V^2
V = sqrt(200)
V=14.14 m/s to double KE
,b.
KE = 1/2 * M * V^2
KE is proportional to square of velocity so doubled=2 times so
2^2=4
Example: if M=5 and V=10:
KE=1/2*5*10^2
KE=250
doubled-
KE=1/2*5*20^2
KE=1000
1000/250=4
◉ a. A 100 g ball is thrown straight up in the air from a height of 1.5
m above the floor. The ball just reaches the ceiling 10 m above the
floor. What was the initial speed of the ball?
, b. What speed will the ball have the instant before it hits the floor?
Answer: a.
Vf^2=Vo^2-2as
2(9.8) (10-1.5)=Vo^2
Vo=12.9m/s
b.
PE=mgh
KE=1/2mv^2
mgh=1/2mv^2
2gh=v^2
v=sqrt(2(9.8)10)
v=14 m/s
◉ a. Calculate the power required for a 1,400 kg car to climb a 10
degree hill at a steady 80 km/hr.
b. Calculate the power required of a 1,400-kg car to pass another car
on a level road accelerating from 90 to 110 km/hr in 6 seconds.
Assume the retarding force on the car is 700 N throughout.
Answer: a.
