A 1200 kg car is moving on the freeway at 65 mph. (A) find the magnitude of its momentum and its kinetic energy in SI units. (b) if a 2400 kg SUV has the same speed asthe 1200 kg car, how much momentum and kinetic energy does it have?
so the answer would be 29.05 m/s for a
No. That is the velocity. Now compute momentum, and KE.
300 000 = (1/2)M x 20^2 so M = 1 500kg
To find the magnitude of momentum, we use the formula:
Momentum (p) = mass (m) × velocity (v)
Given:
Mass of the car (m) = 1200 kg
Velocity of the car (v) = 65 mph
To convert mph to m/s, we use the conversion factor:
1 mph = 0.44704 m/s
(A) Magnitude of Car's Momentum:
First, we convert the velocity from mph to m/s:
65 mph × 0.44704 m/s mph^-1 ≈ 29.06 m/s
Now, we calculate the car's momentum:
Momentum (p) = mass (m) × velocity (v)
p = 1200 kg × 29.06 m/s ≈ 34,872 kg m/s
So, the magnitude of the car's momentum is approximately 34,872 kg m/s.
(B) Magnitude of SUV's Momentum:
Given:
Mass of the SUV (m) = 2400 kg
Velocity of the SUV (v) = 65 mph
Using the same conversion factor, we find the velocity in m/s:
65 mph × 0.44704 m/s mph^-1 ≈ 29.06 m/s
Now, we calculate the SUV's momentum:
Momentum (p) = mass (m) × velocity (v)
p = 2400 kg × 29.06 m/s ≈ 69,744 kg m/s
So, the magnitude of the SUV's momentum is approximately 69,744 kg m/s.
To find the kinetic energy, we use the formula:
Kinetic Energy (KE) = 0.5 × mass (m) × velocity^2 (v^2)
(A) Car's Kinetic Energy:
KE = 0.5 × 1200 kg × (29.06 m/s)^2 ≈ 50,467.2 J
So, the kinetic energy of the car is approximately 50,467.2 Joules.
(B) SUV's Kinetic Energy:
KE = 0.5 × 2400 kg × (29.06 m/s)^2 ≈ 201,868.8 J
So, the kinetic energy of the SUV is approximately 201,868.8 Joules.
on b), twice the mass means twice the momentum and twice the energy.
a) change 65mph to m/s. To check that, put this in your google search window:
65miles/hr in m/s