Answer:

Explanation:
Given:
Initial velocity of the vehicle, 
distance between the car and the tree, 
time taken to respond to the situation, 
acceleration of the car after braking, 
Using equation of motion:
..............(1)
where:
final velocity of the car when it hits the tree
initial velocity of the car when the tree falls
acceleration after the brakes are applied
distance between the tree and the car after the brakes are applied.

Now for this situation the eq. (1) becomes:
(negative sign is for the deceleration after the brake is applied to the car.)
Answer:
d=0.137 m ⇒13.7 cm
Explanation:
Given data
m (Mass)=3.0 kg
α(incline) =34°
Spring Constant (force constant)=120 N/m
d (distance)=?
Solution
F=mg
F=(3.0)(9.8)
F=29.4 N
As we also know that
Force parallel to the incline=FSinα
F=29.4×Sin(34)
F=16.44 N
d(distance)=F/Spring Constant
d(distance)=16.44/120
d(distance)=0.137 m ⇒13.7 cm
Unlike acceleration and velocity, speed does not need to specify the direction of motion. Speed is a scalar quality.
Answer:
a) Fₓ = 23.5 N
b) Net force = Fₓ
Explanation:
An image of the question as described is attached to this solution.
From the image attached, the forces acting on the box include the weight of the box, the normal reaction of the surface on the box, the applied force on the box and the Frictional force opposing the motion of the box (which is negligible and equal to 0)
a) From the diagram, the horizontal component of the force is
Fₓ = 25 cos 20° = 23.49 N = 25 N
b) Again, from the diagram attached, doing a force balance on the box, in the horizontal direction, we obtain
Net force = Fₓ - Frictional force
But frictional force is 0 N
Net force = Fₓ
Hope this Helps!!!