Elsa runs 100m. She takes 20s to run this distance. What is Elsa's average speed?
1 answer:
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Answer:
<h3>The answer is 2.5 g/cm³</h3>Explanation:
The density of a substance can be found by using the formula
From the question we have
We have the final answer as
<h3>2.5 g/cm³</h3>Hope this helps you
Answer: 20.21 kg
Explanation:
The mass hanging from the pulley is pulling the cart. The force by which cart is being pulled is equal to weight of the hanging mass.
⇒F=0.200 kg ×9.8 m/s²=1.96 N
Since there is no other force acting on the cart and there is no friction, so this force will pull the cart.
The Cart covers 1.12 m distance in 4.8 s.
From the equation of motion,
s = u t + 0.5 × a t²
We will find the acceleration of the cart,
Distance covered, s = 1.12 m
Initial velocity, u = 0 ( staring from rest)
Time taken, t = 4.8 s
⇒1.12 m = 0 + 0.5 × a × (4.8 s)²
⇒a = 0.097 m/s²
Now the force which causes this acceleration is:
F = ma
where m is the mass of the cart and a is the acceleration of the cart
⇒1.96 N = m×0.097 m/s²
⇒m = 20.21 kg
Hence, the mass of the cart is 20.21 kg.