Answer: 2.74
Explanation:
We can solve this problem using the stopping distance formula:
Where:
is the distance traveled by the car before it stops
is the car's initial velocity
is the coefficient of friction between the road and the tires
is the acceleration due gravity
Isolating :
Solving:
This is the coefficient of friction
Answer:
If you are sitting in a car undergoing acceleration you will experience a force backwards into the seat.
If you were sitting in a similar seat, on a carousel, and facing the center of rotation you would feel similar force backwards into the seat.
In both cases the acceleration is in the direction that you are facing.
In rotational motion the force producing the acceleration is the centripetal force.
The feeling of being pushed backwards into the seat is a reaction force and in the case of rotational motion this is called the centrifugal force.
The centrifugal force is a reaction force, but it is not the force that produces the acceleration.
PE=MGH. M=3kg, G=9.8m/s^2, H=4m. PE=3*9.8*4. PE =117.6 Joules
Explanation:
(a) You can solve this using kinematics or energy.
Using kinematics:
a = F/m = 90 N / 4 kg = 22.5 m/s²
v₀ = 0 m/s
Δx = 5 m
Find: v
v² = v₀² + 2aΔx
v² = (0 m/s)² + 2 (22.5 m/s²) (5 m)
v = 15 m/s
Using energy:
W = ΔKE
Fd = ½ mv²
(90 N) (5 m) = ½ (4 kg) v²
v = 15 m/s
(b) ΔU = mg Δh
ΔU = (4 kg) (9.8 m/s) (12 m sin 40° − 15 m)
ΔU = -290 J
W = ΔU = -290 J
