Answer:
4 s
Explanation:
u = 19.6 m/s, g = 9.8 m /s^2
Let the time taken to reach the maximum height is t.
Use first equation of motion.
v = u + at
At maximum height, final velocity v is zero.
0 = 19.6 - 9.8 x t
t = 19.6 / 9.8 = 2 s
As the air resistance be negligible, is time taken to reach the ground is also 2 sec.
So, total time taken be the ball to reach at original point = 2 + 2 = 4 s
Jenny is traveling southward. In order to stop, she needs a northward acceleration.
A better way to say it:
Jenny is traveling southward in her bumper car, so the direction of her velocity is south. In order to reduce her velocity to zero, a velocity of equal magnitude but directed north must be added to it. Then the change in velocity is positive northward, and the change in velocity per unit time is acceleration.
Answer:
B
Explanation:
The net force is the force between action and reaction and when this forces are not the same an acceleration is spurred.
Answer:
8 times
Explanation:
Given that You have about 10 quarts of blood in your body. At REST your heart pumps about 5 quarts each minutes.
That means the heart will pump 10 quarts in 2 minutes.
That is half of your blood volume per minute.
If during exercise it can pump 40 quarts per minute, that is, 80 quarts in 2 minutes.
To know how many times does all of your blood complete the cycle around your body during exercise, you must divide 80 quarts by 10 quarts. That is,
80 / 10 = 8
Therefore, your blood complete the cycle around your body 8 times during the exercise.
Answer:
1.) U = 39.2 m/s
2.) t = 4s
Explanation: Given that the
height H = 78.4m
The projectile is fired vertically upwards under the acceleration due to gravity g = 9.8 m/s^2
Let's assume that the maximum height = 78.4m. And at maximum height, final velocity V = 0
Velocity of projections can be achieved by using the formula
V^2 = U^2 - 2gH
g will be negative as the object is moving against the gravity
0 = U^2 - 2 × 9.8 × 78.4
U^2 = 1536.64
U = sqrt( 1536.64 )
U = 39.2 m/s
The time it takes to reach its highest point can be calculated by using the formula;
V = U - gt
Where V = 0
Substitute U and t into the formula
0 = 39.2 - 9.8 × t
9.8t = 39.2
t = 39.2/9.8
t = 4 seconds.
