Answer:
Một vật được ném xiên lên từ đỉnh của một tòa nhà cao 20m với góc 600 so với phương ngang, tốc độ ban đầu là 10m/s. Xác định độ cao cực đại của vật so với mặt đất?
Explanation:
Answer:
Troposphere, stratosphere, mesosphere and thermosphere. The next region is the exosphere, but that region is 500+ km from the Earth's surface.
The answer is the change in kinetic energy
K = 1/2 • mv^2
Change in K = (1/2 • 20 • 10^2) - (1/2 • 20 • 5^2)
Change in K = 1000 - 250 = 750J
Answer:
Part(a): The average acceleration is
during the first 6s.
Part(b): The average acceleration from 6s to 8s is zero.
Explanation:
Part(a):
The average acceleration is defined as the rate at which velocity is changing with respect to time. So if '
', '
' and '
' represents the initial velocity, final velocity, and average acceleration of a particle, then mathematically

where '
' is the time taken by the particle to achieve the velocity '
' starting from initial velocity '
'
Given in the problem,
.
So the average acceleration(
) during the first 6 s will be

Part(b):
During the time between 6 s to 8 s, as mentioned in the problem, the sprinter maintains the constant velocity. So the average acceleration during this time interval will be zero.