A mechanical wave can only travel through matter.
We can look at all the ages of the earth since it’s a big crack is reveals many layers of the earth and we can know about chemicals and metals that were in earth and diffrent times
Answer: B
Explanation:
Given that an object of mass 2 kg starts from rest and is allowed to slide down a frictionless incline so that its height changes by 20 m.
The parameters given from the question are:
Mass M = 2kg
Height h = 20m
Let g = 9.8m/s^2
At the bottom of the incline plane, the object will experience maximum kinetic energy.
From conservative of energy, maximum K.K.E = maximum P.E
Maximum P.E = mgh
Maximum P.E = 2 × 9.8 × 20 = 392 J
But
K.E = 1/2mv^2
Substitute the values of energy and mass into the formula
392 = 1/2 × 2 × V^2
V^2 = 392
V = sqrt( 392 )
V = 19.8 m/s
V = 20 m/s approximately
In order to answer this, we will set up a simple ratio as such:
1 calorie = 4.184 joules
1 kilocalorie = 1000 calories
1 kilocalorie = 4,184 joules
250 kilocalories = x joules
Cross multiplying the second and third equations, we get:
x joules = 4,184 * 250
250 kilocalories are equivalent to 1,046 kJ
Answer: 259.2 KJ
Explanation:
The formula calculate work don in a circuit is given by :-
, where Q is charge and V is the potential difference.
The formula to calculate charge in circuit :-
, where I is current and t is time.
Given : Current : 
Potential difference : 
Time : 
Now, 
Then, 
Hence, the work done = 259.2 KJ
