true.A study has been conducted and suggested that indeed improving muscular strength and endurance or exercising can enhance bone density and stop it from declining whether its due to accidents or old age. Also, because this practice is needed to have stronger and more healthier bones, exercising is always a necessity and should be a habit.
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Answer:
depends the ancient humans or the start of the solar system
Explanation:
if its the humans the earth was in the middle of everything.
but the beginning of the solar system lets say when earth just formed the orbits where unstable and planet ending impacts happed a lot.
ill do the proto planetary disc too
the disc formed the gas giants first then the rockey planets formed out of the disc
Answer:
False
Explanation:
The tension in the chain must be equal to the frictional force acting on the car, not to its weight.
In fact, we have 4 forces acting on the car
- Its weight: downward
- The normal reaction of the road on the car: upward --> this force balances the weight, so the net force along the vertical direction is zero
- The tension in the chain: forward
- The frictional force between the road's surface and the tires of the car: backward
We can consider the horizontal motion only: we are said that the car is moving at constant velocity, so the horizontal acceleration is zero. According to Newton's second law:

zero acceleration means that the resultant of the forces on the car is zero. But there are only 2 forces acting on the car in the horizontal direction: the tension in the chain (forward) and the frictional force (backward). Since their resultant must be zero, it means that the two forces must be equal and opposite: therefore, the tension in the chain must be equal to the frictional force.
Answer:
The velocity of other mass is 3.60 m/s.
Explanation:
Given that,
Mass of first block = 8 kg
mass of second block = 4.3 kg
Speed = 6.7 m/s
We need to calculate the speed of first mass
Using conservation of momentum

where, m₁ =mass of first block
m₂ =mass of second block
m₁ =mass of first block
v₂ =speed of second block
Put the value into the formula



Negative sign represent the opposite direction of initial value.
Hence, The velocity of other mass is 3.60 m/s.
Answer: a) 10.4km
b) 0.62h
C) 17km/h
d) 9.1km/h
Explanation:
A) suppose you move in the positive direction of an x axis, from a first position of x1 = 0 to a second position of x2 at the station. That second position must be at x2 = 8.4 km + 2.0 km = 10.4 km.
B) time interval Dtwlk (= 0.50 h), but we don't know the driving time interval Dt/dr. However, we know that for the drive the displacement Dx/dr is 8.4 km and the average velocity vavg,dr is 70 km/h.
This average velocity is the ratio of the displacement for the drive to the time interval for the drive:
dv = dx/ dt
dt = dx/dv = 8.4/70 = 0.12h
t = ti + two
t = 0.12 + 0.50 = 0.62h
C) avg speed for the entire trip is the ratio of the displacement of 10.4 km for the entire trip to the time interval of 0.62 h for the entire trip.
Avg v = distance/time
10.4/0.62 = 16.8km/h
D) average speed is the ratio of the total distance you move to the total time interval you take to make that move. The total distance is 8.4 km + 2.0 km + 2.0 km = 12.4 km. The total time interval is 0.12 h + 0.50 h + 0.75 h = 1.37 h.
Avg speed = 12.4/1.37 = 9.1km/h