Answer:
v = 14 m/s
= 31.3 mph
The answer would be the same if the mass of the car were 2000 kg
Explanation:
Let V be the final velocity of the car after skidding, and v be the initial velocity of the car. Let a be the acceleration of the car and Δx be the distance the car travels after applying brakes (length of the skid marks). Let Fk be the force of friction between the tyres and the road. Let N be the normal force exerted on the car and μ be the co efficient of kinetic friction.
V^2 = v^2 + 2×a×Δx
Now V, the final velocity is zero as the car stops
0 = v^2 + 2×a×Δx
v^2 = -2×a×Δx
v =√-2×a×Δx .....*
Now applying Newton's Second Law
Fnet = m×a
-Fk = m×a
-μ×N = m×a
-μ×m×g = m×a (The mass cancels out)
a = -μ×g
Substituting the value of a back to equation *
v = √-2×(-μ×g)×Δx
v = √-2×(-0.5×9.8)×20
v = 14 m/s
Therefore the speed the car was travelling with v = 14 m/s
which is equal to 31.3 mph
Now if you were to change the mass of the car to 2000 kg the value for v would still be the same. As it is seen above mass cancels out so it does not influence or affect the value of the velocity obtained.
Answer:
The strength of gravity on the moon is .
Explanation:
We have,
Weight of the backpack, W = 9.2 N
Mass, m = 5 kg
It is required to find the strength of gravity on the moon. Weight of an object is given by :
W = mg
g is strength of gravity on the Moon
So, the strength of gravity on the moon is .
Answer:
Part a)
Part b)
Part c)
Part d)
Part e)
Part f)
Part g)
Explanation:
Part a)
first force is given as
at 35 degree
Second force is given as
at 150 degree
Part b)
Total force is given as
Part c)
as we know
F = ma so object acceleration is given as
Part d)
By kinematics we know that
Part e)
As we know that final position is given as
Part f)
final kinetic energy is given as
Part g)
final kinetic energy is given as