Physics kinetic energy
posted by Aisumi .
Okay the equation for kinetic energy is = 1/2mv^2 so how would i figure this out??
If a semitruck decreases its speed from 10 m/s to 5 m/s, its new Kinetic Energy is:
a)4 times its old Kinetic Energy
b)2 times its old Kinetic Energy
c)1/2 its old Kinetic Energy
d)1/4 its old Kinetic Energy
okay since the v is half of what it was would it be c????

Physics kinetic energy 
Jordan
because v is the only thing changing the value of m is not relevant. to find out what would happen to the energy we compare the differences in v
ie 10^2 = 100
5^2 = 25
since the new v value is a quarter of the previous value the answer is (d)
alternatively, your reasoning before is correct but you have forgotten that the v value is squared ie 0.5^2 = 0.25
Respond to this Question
Similar Questions

physicsenergy conservation
when you apply the brakes of a car its kinetic energy or energy of motion decreases. a)to what form of energy is the kinetic energy converted? 
physics kinetic energy
a) if a particle's speed decreases by a factor of four, by what factor does its kinetic energy change? 
Physical Science
Can someone please check these answers for me? 
Physics
A 245 g particle is released from rest at point A inside a smooth hemispherical bowl of radius 35.0 cm, as shown in Figure 521. (a) Calculate the gravitational potential energy at A relative to B. 1 . (b) Calculate the particle's … 
Physics
A 5.36 kg object falls freely (ignore air resistance), after being dropped from rest. Determine the initial kinetic energy, the final kinetic energy, and the change in kinetic energy for the following. (a) first meter of fall initial … 
Physics
A rolling barrel with initial velocity 20 m/s encounters a hill 10m tall to slow it down 1. state where its angular speed is 0 2. state where its rotational kinetic energy will be 0 3. state where its translation kinetic energy will … 
Chem please help
An object A has half the mass and twice the velocity of object B. How are the kinetic energies of A and B related? 
science
A ball sitting on the top of a table has potential energy but no kinetic energy. How do potential and kinetic energy change as the ball falls off the table to the floor? 
science
A ball sitting on the top of a table has potential energy but no kinetic energy. How do potential and kinetic energy change as the ball falls off the table to the floor? 
Science
which of the following is true about kinetic energy select all that apply A as an objects speed increases kinetic energy decreases B only moving objects have kinetic energy ••• C kinetic energy increases as an objects height …