160. A driver with a car of mass 2 tons, moving at speed $36\,\dfrac{\text{km}}{\text{h}}$ on a straight horizontal road, applies the brakes upon seeing a red light. The car stops after traveling $4\,\text{m}$. How many Newtons is the braking friction force applied to the car?
(1) $7500$ (2) $12500$ (3) $15000$ (4) $25000$
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Speeds of two identical cars are $u$ and $4u$ at the specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is
(1) $1 : 1$
(2) $1 : 4$
(3) $1 : 8$
(4) $1 : 16$

A car, moving with a speed of $50 \mathrm{~km} / \mathrm{hr}$, can be stopped by brakes after at least 6 m. If the same car is moving at a speed of $100 \mathrm{~km} / \mathrm{hr}$, the minimum stopping distance is
(1) 12 m
(2) 18 m
(3) 24 m
(4) 6 m

An automobile travelling with speed of $60 \mathrm {~km} / \mathrm { h }$, can brake to stop within a distance of 20 cm . If the car is going twice as fast, i.e $120 \mathrm {~km} / \mathrm { h }$, the stopping distance will be
(1) 20 m
(2) 40 m
(3) 60 m
(4) 80 m

For a train engine moving with speed of $20 \mathrm {~ms} ^ { - 1 }$, the driver must apply brakes at a distance of 500 m before the station for the train to come to rest at the station. If the brakes were applied at half of this distance, the train engine would cross the station with speed $\sqrt { x } \mathrm {~ms} ^ { - 1 }$. The value of $x$ is $\_\_\_\_$ . (Assuming same retardation is produced by brakes)

Q21. A bus moving along a straight highway with speed of $72 \mathrm {~km} / \mathrm { h }$ is brought to halt within $4 s$ after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is $\_\_\_\_$ m.

Q2. Two cars are travelling towards each other at speed of $20 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ each. When the cars are 300 m apart, both the drivers apply brakes and the cars retard at the rate of $2 \mathrm {~m} \mathrm {~s} ^ { - 2 }$. The distance between them when they come to rest is :
(1) 200 m
(2) 100 m
(3) 50 m
(4) 25 m

A body is projected up the smooth incline plane having angle of inclination $\theta$ with the horizontal as shown in the figure. Find the $v > 0$ distance covered before stopping. (A) $\frac { \mathrm { u } ^ { 2 } } { 2 \mathrm { gsin } \theta }$ (B) $\frac { u ^ { 2 } } { 2 g \tan \theta }$ (C) $\frac { \mathrm { u } ^ { 2 } } { 2 \mathrm {~g} }$ (D) $\frac { u ^ { 2 } } { 2 g \cos \theta }$