Answer:
there are 25 kg objective travelling at 2m/s to the right.
Answer:
5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Explanation:
The concept to solve this problem is given by Energy Transferred, the equation is given by,

Where,
Q= Energy transferred
m = mass of water
c = specific heat capacity
Temperature change (K or °C)
Replacing the values where mass is 50g and temperature is 80°C to 0°C we have,



Then we can calculate the heat absorbed by m grams of ice at 0°C, then

How Q_1=Q_2, so



Then 5.5g of ice melts when a 50g chunk of iron at 80°C is dropped into a cavity
Using the given equation:
di = 20.0 * 10.0 / 20.0 - 10.0
di = 200/10
di = 20.0 cm
The answer is A.
Explanation:
Given that,
A ball is tossed straight up with an initial speed of 30 m/s
We need to find the height it will go and the time it takes in the air.
At its maximum height, its final speed, v = 0 and it will move under the action of gravity. Using equation of motion :
v = u +at
Here, a = -g
v = u -gt
i.e. u = gt

So, the time for upward motion is 3.06 seconds. It means that it will in air for 3.06×2 = 6.12 seconds
Let d is the maximum distance covered by it.

Putting all values

Hence, it will go to a height of 45.91 m and it will in the air for 6.12 seconds.