Question

A robot shoots a ball vertically upwards at an initial speed of 30 m/s. What is the distance travelled by the ball 5 s after the shoot? (g = 10m/s2)
A. 25 m
B. 45 m
C. 65 m
D. 75 m
The correct answer is C, but I need detailed explanation

Answer 1

Answer:

C. 65m

Explanation:

u = 30m/s

a= -30m/s 2

v=0 ( at the highest place)

v = u + at

0 = 30 - 10t

t= 3s

s = ut + 1/2at2

=90-5 × 3×3

=45m

u = 0 ( after falling from the highest place)

t = 5-3 = 2s

s= 0 + 1/2at2

= 5 × 4

= 20 m

So, s= 45+ 20

=65m

Answer 2

Answer:

By using the equations of motion, the distance traveled by the ball 5 s after the shoot is (A.) 25 m

Explanation:

Given:

The initial velocity (u) = 30 m/s

Time (t) = 5 seconds

Acceleration due to gravity (g) = -10 m/$s^{2}$

(Negative sign because the ball is shooted vertically upward)

Now, we will use the three equations of motion to calculate the distance traveled.

The three equations of motion are,

$v = u+at$

$s = ut + \frac{1}{2} at^{2}$

$v^{2} -u^{2} = 2as$

Since the given parameters are initial velocity, time taken, and acceleration due to gravity and we need to calculate the distance traveled by the ball, which can be easily calculated using the second equation of motion,

So, we have

$s = ut + \frac{1}{2} at^{2}$

Now, applying this equation and putting the given values, we have:

$s = 30 * 5 + \frac{1}{2} *10 * (5)^{2} \\s = 150 - 125\\s = 25 m$

Therefore,  the distance traveled by the ball 5 s after the shoot is A. 25 m

To read more about the equations of motion, visit

https://brainly.in/question/53830375

https://brainly.in/question/42493470

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