A stone is dropped from a height of 20 m. How long will it take to reach the gro

₹0.0

Question: A stone is dropped from a height of 20 m. How long will it take to reach the ground?

Options:

Correct Answer: 2 s

Solution:

Using h = (1/2)gt², where h = 20 m and g = 9.8 m/s², we have 20 = (1/2)*9.8*t². Solving gives t² = 4.08, so t ≈ 2 s.

A stone is dropped from a height of 20 m. How long will it take to reach the ground?

A stone is dropped from a height of 20 m. How long will it take to reach the ground?

Step 1: Identify the height from which the stone is dropped. In this case, the height (h) is 20 meters.
Step 2: Understand that the formula to calculate the time (t) it takes for an object to fall from a height is h = (1/2)gt², where g is the acceleration due to gravity (approximately 9.8 m/s²).
Step 3: Substitute the known values into the formula. We have h = 20 m and g = 9.8 m/s², so the equation becomes 20 = (1/2) * 9.8 * t².
Step 4: Simplify the equation. First, calculate (1/2) * 9.8, which equals 4.9. Now the equation is 20 = 4.9 * t².
Step 5: To isolate t², divide both sides of the equation by 4.9. This gives t² = 20 / 4.9.
Step 6: Calculate 20 / 4.9, which is approximately 4.08. So now we have t² = 4.08.
Step 7: To find t, take the square root of 4.08. This gives t ≈ 2 seconds.

Kinematics – The question tests understanding of the equations of motion, specifically the relationship between distance, acceleration due to gravity, and time.
Free Fall – It assesses knowledge of free fall motion, where an object is dropped and accelerates due to gravity.