Before Copernicus most people were thinking that the Earth is at center of universe. In 1609 Galileo observed sky through his home made telescope.
He found 4 moons orbiting Jupiter..It was a proof that bodies are orbiting other planets and not earth alone. <span>He found the crescent shape of Venus through his telescope and this could happen only if Sun is at center.</span>
Explanation:
The area between the speed-time graph f a body and time axis measures the distance travelled by the body
Answer:
4km/hr
Explanation:
There are 60 minute in an hour. If you divided 60 by 30 minutes you’d get 2. 2x 2km is 4km and 30x 2 is 60/an hour
Answer:
81 km/h W52°S
Explanation:
The bird's initial velocity is 25 km/h, 45° east of north. The components of the velocity are:
aₓ = 25 sin 45
aᵧ = 25 cos 45
The bird's final velocity is 56 km/h, 35° west of south. The components of the velocity are:
bₓ = -56 sin 35
bᵧ = -56 cos 35
The change in velocity is the final velocity minus the initial velocity.
cₓ = bₓ − aₓ
cₓ = -56 sin 35 − 25 sin 45
cₓ ≈ -49.8
cᵧ = bᵧ − aᵧ
cᵧ = -56 cos 35 − 25 cos 45
cᵧ ≈ -63.6
The magnitude is found using Pythagorean theorem:
c² = cₓ² + cᵧ²
c² = (-49.8)² + (-63.6)²
c ≈ 81 km/h
The direction is found using trigonometry:
θ = atan(cᵧ / cₓ)
θ = atan(-63.6 / -49.8)
θ ≈ 52°
The change in velocity is 81 km/h W52°S.