In order to find the force (F), you would have to use the formula for it:
F=ma
where m is mass and a is acceleration.
In the problem, the mass is 2.85kg and the acceleration is 4.9m/s^2.
Therefore,
F=2.85kg(4.9m/s^2)
F=13.965kg(m/s^2)
Since N=kg(m/s^2)
F=13.965N
And because the problem requires that we use only 2 significant figures,
F=13N
Therefore, the student must exert 13N of force.
Answer:
(3) 53°
Explanation:
We want to measure the angle that the rains form with the vertical wind shield, so we have to measure the angle relative to the vertical. This means that we can write the following equation

where
is the speed of the rain, which travels vertically
is the speed of the bus, which travels horizontally
Substituting, we find

Answer:
The correct option is (c) "it bounces the light towards a focal point"
Explanation:
There are two types of spherical mirrors i.e. concave and convex.
A concave mirror is a type of spherical mirror that is curved inwards. For this type of mirror the rays of light are bounced back and converge to the focal point of the mirror.
So, the correct option is (c).
To solve this problem it is necessary to apply the concepts related to Normal Force, frictional force, kinematic equations of motion and Newton's second law.
From the kinematic equations of motion we know that the relationship of acceleration, velocity and distance is given by

Where,
Final velocity
Initial Velocity
a = Acceleration
x = Displacement
Acceleration can be expressed in terms of the drag coefficient by means of
Frictional Force
Force by Newton's second Law
Where,
m = mass
a= acceleration
Kinetic frictional coefficient
g = Gravity
Equating both equation we have that



Therefore,


Re-arrange to find x,

The distance traveled by the car depends on the coefficient of kinetic friction, acceleration due to gravity and initial velocity, therefore the three cars will stop at the same distance.
Answer:
d = 44.64 m
Explanation:
Given that,
Net force acting on the car, F = -8750 N
The mass of the car, m = 1250 kg
Initial speed of the car, u = 25 m/s
Final speed, v = 0 (it stops)
The formula for the net force is :
F = ma
a is acceleration of the car

Let d be the breaking distance. It can be calculated using third equation of motion as :

So, the required distance covered by the car is 44.64 m.