# How about helping me with these problems?

1- Ann is driving down a street at 60 km/h. Suddenly a child runs into the street. If it takes Ann 0.774 s to react and apply the brakes, how far will she have moved before she begins to slow down? Answer in units of m.

2- A glacier advances at 4.8 × 10−6 cm/s. How far will it move in 75000 s? Answer in units of cm. How far will it move in 6.4 y? Answer in units of cm.

3- A polar bear starts at the North Pole. It travels 1 km South, then 1 km East, then 1 km North to return to its starting point. This trip takes 0.5 h. What was the bear’s average velocity? Answer in units of km/h.

1. Direction means nothing in this question. The bear traveled 3 km in 0.5 hours. so that’s your speed. 3/0.5 km/h. Simplify the fraction and get 6km/h.
1. Multiply the time and the speed, the units cancel.

4.8x10^-6 X 75000s = 3.6 cm

Find the total seconds in a year.

60 seconds x 60 minutes x 24 hours x 365 days = 31536000 seconds.

Multiply by the speed, the units cancel.

4.8x10^-6 X 31536000s = 1513.728 cm

1. Convert 0.774 seconds to hours.

0.774s X 1/360h/s = 0.774/360 = 0.00215h

Multiply by the speed, the units cancel.

0.00215 X 60km/h = 0.129km

Convert to meters from kilometers

0.129km X 1000m/km = 129 Meters

always convert to m.s^-1 when working with equations of motion,

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