3 years ago

Newtons second law of motion-skateboard

Physics

1 answer:

Darya [45]3 years ago

6 0

Answer:

??? I don't get it, please explain. What is your question????

Explanation:

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A ball is tossed vertically upwards with a speed of 5.0 m s–1. After how many seconds will the ball return to its initial positi

mezya [45]

Answer:

1.02 seconds

Explanation:

Initial velocity = u = 5 m/s

t = Time taken

s = Displacement travelled = 0

a = Acceleration due to gravity = -9.81 m/s² (negative sign due to direction)

Equation of motion

$s=ut+\frac{1}{2}at^2\\\Rightarrow 0=5t+\frac{1}{2}-9.81\times t^2\\\Rightarrow 0=5t-4.905t^2\\\Rightarrow 0=t(5-4.905t)\\\Rightarro 0=5-4.905t\\\Rightarrow t=\frac{-5}{-4.905}=1.02\ seconds$

So, time taken to return to its initial position is 1.02 seconds

7 0

4 years ago

lf an object's velocity changes from 25 meters per second to 15 meters per second in 2.0 seconds, the magnitude of the object's

Mila [183]

Answer:

-5 m/s^2

Explanation:

$acceleration = \frac{change \: in \: velocity}{time} \\ \\ = \frac{15 - 25}{2} \\ \\ = \frac{ - 10}{2} \\ \\ = - 5 \: m {s}^{ - 2} \\ \\ negative \: sign \: represents \: that \: \\ object \: is \: slowing \: down.$