A ball is thrown vertically upwards with a speed 70 m/s . The distance travelled by the ball in its seventh second of motion will be [g = 10 m / s2]

Question

A ball is thrown vertically upwards with a speed 70 m/s . The distance travelled by the ball in its seventh second of motion will be [g = 10 m / s2] (A) 10 m (B) 2.1 m (C) 3.4 m (D) 5 m

Tardigrade Admin · Accepted Answer

Let distance travelled in seventh second is

S

u & a =

Intial velocity and acceleration
Using the equation of motion

S_{n t h} = u + \frac{a}{2} (2 n - 1) S_{n t h} = 70 - \frac{10}{2} (2 \times 7 - 1) S_{7 t h} = 70 - \frac{10}{2} \times 13 S_{7 t h} = 70 - 65 S_{7 t h} = 5 m

Q. A ball is thrown vertically upwards with a speed $70 m / s$ . The distance travelled by the ball in its seventh second of motion will be $[g = 10 m / s^{2}]$

$10 m$

$2.1 m$

$3.4 m$

$5 m$

Let distance travelled in seventh second is $S$
$u & a =$ Intial velocity and acceleration
Using the equation of motion
$S_{n t h} = u + \frac{a}{2} (2 n - 1) S_{n t h} = 70 - \frac{10}{2} (2 \times 7 - 1) S_{7 t h} = 70 - \frac{10}{2} \times 13 S_{7 t h} = 70 - 65 S_{7 t h} = 5 m$

Q. A ball is thrown vertically upwards with a speed 70m/s . The distance travelled by the ball in its seventh second of motion will be [g=10m/s2]

10m

2.1m

3.4m

5m